The present invention relates to activated carbon filtration systems, and more particularly to apparatus and methods for transferring granulated carbon charges within such systems.
Industry and the public have become increasingly aware of the adverse consequences of contaminants in water supplies and in waste water. Government regulations have been promulgated requiring industry to remove defined toxic chemicals from waste water streams to eliminate or substantially reduce ground water contamination. Activated carbon adsorption is an effective process for the purification of water contaminated by organic compounds. Granular activated carbon (GAC) improves water quality by reducing organic contaminants, decoloring, and controlling odors and by recovering solvents. One or more carbon canisters or columns are provided in an activated carbon treatment system. The contaminated influent, such as ground water, is directed through the carbon columns in a down flow manner. Filtering can occur either in parallel or in series when multiple columns are provided.
Because the activated carbon adsorbs "toxic chemicals" as defined by government regulations, the carbon used in filtering must be handled as a toxic material. The carbon after filtering may contain one or more of the following defined toxic chemicals: hydrocarbons, solvents, volatile organic carbons, amines, aldehydes, pesticides, or PCB's.
Prior to the present invention, the carbon charges within such systems were moved or transferred by (1) first forming the carbon into a slurry and (2) pumping the slurry. Such procedure results in direct handling of the contaminated carbon and therefore requires the government-defined treatment and handling of the equipment contacting the carbon. Known methods of moving the contaminated carbon charges are therefore relatively time-consuming and expensive.